What is CLL (chronic lymphocytic leukemia) and what is SLL (small lymphocytic lymphoma)?

What is CLL (chronic lymphocytic leukemia) and what is SLL (small lymphocytic lymphoma)?

CLL also known as CLL/SLL or chronic lymphocytic leukemia/small lymphocytic lymphoma is a blood cancer, specifically of a type of white blood cell called the B-lymphocyte. It is the most common leukemia in adults in North America. In CLL there is a progressive accumulation of too many incompetent, mature lymphocytes, which are usually monoclonal or genetically identical.

To confuse matters, besides being a type of leukemia, it is also classified as a type of non-Hodgkin’s Lymphoma (NHL).

So CLL is both a leukemia and a lymphoma at the same time.

SLL is best understood as a different stage of CLL where there are not a significant number of cancer cells in the blood stream.